Can't connect to ec2 instance

Hello,

Have you checked the status of your EC2 instance through status checks?

It’s possible that an internal issue with the instance is preventing SSH access. In this case, you can diagnose the problem using status checks.

Status checks are performed every minute, returning a pass or a fail status. If all checks pass, the overall status of the instance is OK. If one or more checks fail, the overall status is impaired.

For example, if the status checks show “1/2 checks passed,” you can try stopping and restarting the instance.

For more details, please refer to the following: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/monitoring-system-instance-status-check.html

If you’ve already confirmed that the status checks are normal, you can check the following:

1. If you're not using the Default VPC, check whether the routing table has a route to the Internet Gateway.
2. If you're not using the Default VPC, ensure that the Internet Gateway is assigned to the subnet where your EC2 instance is located.
3. Check the EC2's Monitoring section to see if CloudWatch metrics are being recorded properly. If there’s an issue, you may want to try restarting the instance.

hello, verify that your instance is ready, verify the following: In the Instance state column, verify that your instance is in the running state. In the Status check column, verify that your instance has passed the two status checks.

Hello,

You can set up the VPC Reachability Analyzer as follows:

1. In the Path Source section, select Internet Gateways as the Source type.
2. In the Path Source section, choose the Internet Gateway of the VPC where the instance is located as the Source.
3. In the Path Destination section, select Instances as the Destination type.
4. Choose the instance as the Destination.

If the Reachability status is "Reachable," it means that the network settings on AWS are correctly configured. If the status is "Not reachable," you can get hints in the Explanation section.

If the Reachability status is "Reachable," the issue may be internal to the instance. You can try accessing the instance using Session Manager to investigate internal issues. Keep in mind that using Session Manager incurs charges.

Prerequisite: To use Session Manager, the instance must have the appropriate IAM permissions. Follow these steps to apply an IAM role:

1. Select the instance, click the Actions button, and choose Modify IAM role.
2. Click Create new IAM role, which will take you to the IAM service.
3. Click Create role, and set the Trusted entity type to AWS service. Choose EC2 as the use case.
4. In the Permissions policies, search for and select the AmazonEC2RoleforSSM AWS Managed Policy.
5. Enter a name for the role, create the role, and then apply it to the instance.

You can install the agent required for Session Manager by following these steps:

1. Stop the instance.
2. Click the Actions button, then select Instance Settings, and choose Edit user data.
3. Enter the following user_data value (for Amazon Linux 2023):

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#!/bin/bash
sudo yum install -y https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/latest/linux_amd64/amazon-ssm-agent.rpm
sudo systemctl start amazon-ssm-agent
--//--

4. Start the instance.
5. Click the Connect button, then select Session Manager to attempt connection through Session Manager.

If you cannot connect and see a message saying the SSM Agent is not connected, it may indicate an issue with the environment, and the installation may not have completed successfully. You can refer to the appropriate installation methods for each environment in the AWS documentation and change this section for your environment.

sudo yum install -y https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/latest/linux_amd64/amazon-ssm-agent.rpm
sudo systemctl start amazon-ssm-agent

If the connection is successful but the SSM console cannot connect, this suggests that the instance may have an internal issue that cannot be resolved. You could consider using user_data to disable internal routing tables or firewalls as a last resort.

Have you changed the inbound rules of the security group assigned to the instance? If you're using the Amazon EC2 console to connect to your instance using EC2 Instance Connect, you need an inbound rule that allows SSH traffic from the EC2 Instance Connect service. For the instructions for configuring this rule, please see the following AWS documentation: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-connect-tutorial.html#eic-tut1-task2